Thomas henderson



(No Model.)

T HENDERSON. FURNACE FRONT AND- DOOR. No. 255,784. Patented Apr. 4,1882.

ing the outer plate cool.

UNITED STATES PATENT OFFI E.

THOMAS HENDERSOR OF BIRKEEHEAD, COUNTY OF CHESTER, ENGLAND.

FURNACE FRONT AND DOOR.

SPECIFICATION forming part of Letters Patent No. 255,784, dated April 4-,, 1852. Application filed December 20,1881. (No model.) Patented in England February 24, 1880.

To all whom it may concern: 7 I

Be it known that I, THoMAs HENDERSON, of Birkenhead, in the county of Chester, England, have invented certain new and useful Improvements in Furnace Fronts and Doors, (for which I have received Letters Patent in Great Britain, dated February 24, 1880, and numbered 800;) and I do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same.

The object of my invention is to provide a furnace front and door that will prevent the heat from the fire from radiating into the stokehole, and through which at the same time a constant current of air is allowed to pass into the furnace to promote combustion, and also providei'or the sulphurousflames andothergaseous matters and heated air from the clinkers, when raked out of the fire, to pass up through the furnace into the chimney or flue.

I construct myfurnace-trontdouble, with the inside plate next 'the fire perforated, through which a constant current of air passes, the air thus traversing becoming heated before entering the furnace, while at the same time keepplate I cast in one piece with the door, forming a V-shaped casting, which is pivoted in cheeks projectingfrorn the furnace-front. This is counterweighted or held in equilibrium by a spring or weight, so as to remain in any position required. In stoking the door is pushed inward until the door takes the place ofthe other dead-plate,and for clearing out the clinker it is still further depressed, leaving a space for the clinker to fall through, and the sulphurous and other gases escaping from the clinker to pass to the flue, while the dead-plate and door form a shield for the stokers legs from the heat of the falling clinkers, and also prevents the radiated heat from entering the stoke-hole.

In the accompanying drawings, Figure 1 is a perspective view of my furnace-front. Fig. 2 is a front elevation of the same; Fig. 3,a vertical section, broken partly through the furnace-front by the side of the door, on'the line was, the door itself being shown in the position which it occupies when firing is going on; Fig. 4, a vertical section through the line 3 y,

Part of the dead the door being shown closed. Fig. 5 isa similar section with thedoor shown in the position for cleaning out clinkers.

Referringnowto the accompanyingdrawings, A represents the furnace-front, and B perforations in the front for the admission of air; 0, the chamber in front for keeping the front cool and for heating the air which passes through it tothe furnace. This chamber extends over the entire back of the furnace-front, except where the door-frame comes in.

D is the back plate of the furnace-front, perforated at its bottom, so as to admit air into the furnace.

E are cheeks on the furnace-front, and F are sockets or holes in the same.

G is the fire-door, and H the dead-plate, which are preferably castin one piece, as shown.

I is the shaft upon which the door G is carried, said shaft being supported in the holes or sockets F. r

J is a spiral spring coiled around the shaft I, one end of said spring being attached to the furnace-front and the other to the door. This spring counter-balances the tendency of the door and dead-plate to fall into the position shown in Fig. 5.

A balance-weight or other description of spring may be used, if desired, instead of the spring shown and described.

The door G, which is of the same length as the front dead-plate, H, is provided with a perforated and perpendicular plate, K, next the furnace, the space between the parts being opened for the entrance of air from below, en-

tering through the aperture L.

The manner of using it is as follows: Furnace with door closed, as in Figs. 1, 2, and 4, requiring charging, the fireman pushes the door with his shovel or with a handle into the position shown in Fig. 3. The door then 00- cupies the place of the dead-plate. He then fires up, and when done changes the position of the door to its normal position, as in Figs.

l and 4. But when cleaning out, however, he

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diated heat from the incandescent clinker entering the boiler-room. The sulphurous fumes and other gaseous matters, with the hot air from the clinkers, pass up through the vacant space left by the dead-plate, through the furnace, into the chimney without contaminating the air of the stoke-hole. The fireman can in the meantime again supply the furnace with fuel without the inconvenience of the radiation from the clinker and the sulphurous and other fumes therefrom, which in ordinary arrangements are so annoying. The furnace-front, too, is kept cool, the furnace supplied with heated air above the bed, and the air drawn from the stoke-hole to the improvement of the ventilation by the arrangement of the air-passages in the furnace-front. The air enters through the perforations B, circulates all over the front in the hollow chambers between A and D, and, heated by the passage through the 'chamber 0, escapes through perforations I? over or under the dead-plate, or both over and under, according as door'T is placed as shown or pointing up or down.

An opening, L,in the extension of the deadplate permits air to enter and pass through the perforated plate K, and when the door is swung down as in Fig. 3, gases escaping from the front of the ash-pit will reenter through the same openings, L and K.

I am aware that a hinged or dumpingdeadplate arranged to drop and permit the dumping of the ashes, clinker, or fire directly into the ash-pit without passing through the firedoor has been proposed, and I am likewise aware that dampers and furnace-doors have been counterbalanced to cause them to stand at any adjustment desired. I-Ience I do not broadly claim these features. I am not, however, aware that the dumping dead-plate and the door have ever before been formed in one piece or adapted to operate in unison, as herein described, though an air-inlet in the deadplate has been controlled by the movements of the door through intermediate mechanism.

Having thus described my invention, what I claim is l. A furnace-front having the door and deadplate or a continuation of the dead-plate constructed in one piece and arranged substantially as described, whereby said parts are adapted to be rotated upon an axis, substantially as and for the purposes described.

2. Ina furnace-front, the combination of a door and a dead-plate or continuation thereof, the top of the door and the end of the dead plate or continuation being equidistant from a common axis about which they rotate when required, substantially as shown and described.

3. In afurnace-front, a counterbalanced door, G, mounted upon a shaft, I, on a level with the furnace-bottom, whereby said doormay be brought to a level with the bars and caused to open the entire door-space.

4. In a furnace-front, the combination of a fire-door, G, supporting-shaft F at the lower edge of said door, and cheek-pieces E, carrying said shaft, the parts being arranged substantially as shown and described, whereby the door is adapted to hang down and act as a shield against the heat of clinker, 850., in the ash-pit and to leave an unobstructed ch argeopening, as explained 5. In a furnacefront, a door mounted and adapted to swing upon a horizontal axis, sub-' stantially as explained, and thereby to open a passage for the discharge of clinker to the ashpit, and another for the return of the gases, &c., into the furnace.

6. In combination with the door G, the supporting shaft or axis F at the lower edge or side of the door, whereby the latter is supported and adapted to fall below the chargeopening, as explained, and the counterbalanced spring J, applied as shown and described, to hold the door as adjusted.

7. Thecombination of theplain uuperforated door G,dead-plate or continuation of the deadplate,having orifices L, and vertical perforated plate K, inclosing an air-space from which the air is brought from the ash-pit over heated surfaces into the furnace, substantially as described.

8. The dead-plate formed in two parts, one

stationary and like an ordinary dead-plate,

and the other, H, projecting beyond the internal face of the furnace and fixed to the door, so that as the door opens the portion of the dead-plate H nearest to it moves with it, and thus leaves a vacant space for clinkers to be thrown down.

THOS. HENDERSON.

Witnesses:

J. O. OBRIEN, J osEPH JAMES ROYDEN.

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